The Bad

- Large size not for everyone
- Battery life average at best
- Weak speaker volume

Sony surprised the smartphone market when it launched the Xperia Z Ultra in late June. With display dimensions at 6.4-inches firmly pushing its way into the small 7-inch tablet segment, it has been pitched as a large smartphone for users who want the biggest possible display that they can still fit comfortably into a jacket pocket. There is currently no smartphone with a larger display on the market, with even Samsung's phablets left trailing in its wake. But is bigger necessarily better?

Design and construction

The Sony Xperia Z Ultra is the latest embodiment of Sony's smartphone design language for 2013. The themes include the extensive use of glass on both the front and back of the device, thin bezels on the sides with larger bezels at the top and bottom of the device The solid aluminum side edges of the device are flat, but taper to both the front and rear of the device creating to help improve comfort. The build quality and feel in the hand is also excellent and conveys a real sense of quality and prestige.

The Xperia Z Ultra also continues with Sony's integration of water and dust proofing technology in its construction. The Xperia Z Ultra achieves the higher IP58 standard for dust and waterproofing with the ability to remain fully functional after being submerged in over 3-feet of water for up to 30 mins. It also uses Asahi Dragontrail glass that is both scratch resistant and shatterproof, which is a good thing given the amount of glass used in the design.

The Xperia Z Ultra also uses Sony's Omnibalance engineering approach that helps to evenly spread the weight of the device in the hand, making this large, 7-inch long, device surprisingly comfortable to hold. This best achieved by holding the device in away from the palm of your hand where you might normally situate your smartphone, and towards the tips of your fingers. Despite glass covering the entire front and rear panels, Sony has also managed to keep the Xperia Z Ultra's weight down to just 212 grams while keeping its profile to just 0.26-inches thin. Yes, it is an enormous phone, but Sony has done everything it can to keep it both manageable and usable.

Display

The Xperia Z Ultra really is all about the display. The only reason you would want a device this size as a smartphone is if the display makes it worth taking the extra effort to carry around with you. Thankfully, Sony has completely delivered on this front. It is one of the best mobile displays we have ever seen, incorporating Sony's unique Triluminos display technology with a 1080p resolution at 344 pixels per inch. Unlike some makers that give a funky sounding marketing name to the display in their device, which amounts to nothing actually special, Triluminos really is a different type of LCD display technology.

Briefly, Triluminos display technology is able to produce a 50 percent wider color gamut than a regular LCD display by using quantum dots, which a light emitting nano particles. To help exercise specific control over the wavelength of light emitted from each quantum particle, Sony utilizes a blue LED backlight instead of a traditional white backlight that causes the film of quantum dots to emit much more pure, and therefore richer, RGB colors. To this is added Sony's proprietary X-Reality tech that uses software algorithms to separately analyse and optimize image texture, outline, contrast and color. It all amounts to an outstanding visual experience that is also quite addictive.

You can find yourself mesmerized by the image quality and sharpness at times with games and movies looking especially impressive. The thinness of the Xperia Z Ultra also makes holding the device in landscape mode easy letting the display take center stage as you are not distracted by any issues of discomfort or awkwardness. The larger bezels at the each end of the device also help in this regard as you quickly become immersed in the visual feast. Viewing angles are excellent, with the only issues we experienced being that brightness dims slightly when viewed from extreme angles. Overall display brightness is not quite as bright as the outstanding display on the HTC One, meaning that outdoor use in bright light conditions is not optimal.

Camera

The Xperia Z Ultra uses an 8-megapixel Sony Exmor RS sensor with back side illumination that is capable of taking still images at a resolution of 3264x2448 pixels. An interesting omission is the inclusion of any type of flash, although it is possible that Sony dropped this because of the thermal design profile of the device. Whether or not the omission of a flash is a problem will depend on the user - it is not a deal killer for us, but it might be for others. However, Sony also packs in a wide range of other software-based features to create very solid, if not exceptional, photo results, while the Exmor RS sensor is designed to optimize image performance in low light conditions.

This includes a continuous burst mode, HDR for photos and videos, face detection, image stabilizing, object tracking, smile shutter, scene recognition, superior auto, and touch focus. You can also take direct control of white balance adjustment, exposure, metering, ISO and filters to create images to your fine-tuned taste. There are more settings, but suffice to say there is more than enough functionality and capability to take some pretty decent images as you can see from our untouched photos embedded below. Video capabilities are also very good with Sony being one of the few to offer HDR in video mode. It can shoot videos in 1080p at 30fps.

Performance

The Sony Xperia Z Ultra is one of the first smartphones to ship with Qualcomm's latest Snapdragon 800 quad-core processor. In this guise it is clocked at 2.2GHz and is matched with 2GB of RAM. When you add in Qualcomm's latest generation Adreno 330 GPU you have what amounts to one of the very fastest devices that you can buy. Thankfully Sony's Android interface is a relatively light skin, and while the Xperia Z Ultra runs the superseded Android 4.2.2 'Jelly Bean,' instead of the recently released Android 4.3 'Jelly Bean,' the Xperia Z Ultra offers a very slick, stutter-free user experience that will keep both power users and the average user very happy. As is always the case, we ran the Xperia Z Ultra through some benchmarks to get some objective performance figures.

As you can see from the AnTuTu benchmark, the Xperia Z Ultra is at the top end of device performance and blows past the Snapdragon 600 chipset as seen in early 2013 flagship devices including the Samsung Galaxy S4 and the HTC One. Yet at the same time as offering significantly faster performance, the Snapdragon 800 is also up to 20 percent more power efficient, managing to deliver what some might consider mutually exclusive outcomes simultaneously.

Similarly the new GeekBench 3 result highlights the raw processing performance of the Snapdragon 800 chipset lying at the heart of the Xperia Z Ultra. It scored 2657 for multithreaded performance and an impressive 900 for single core performance as well. The single core measure is actually good reference point for a device's real world speed as most apps are not specifically optimized for multi-core processors. As a point of comparison, the iPhone 5 with its dual-core A6 processor scores a still competitive 716 on the single-core GeekBench 3 score, while it produces a score of 1293 for the multi-core test.

The Adreno 330 GPU is also at the bleeding edge of mobile graphics performance with the with the Xperia Z Ultra returning a hugely impressive score of 11925 on the Futuremark 3DMark Ice Storm Extreme test. This compares very favourably with the 6755 returned by the HTC One Google Play Edition. Given how spectacular the Xperia Z Ultra display is, the combination of its 6.4-inch Triluminos display with the Adreno 330 GPU makes it one of the best touchscreen mobile gaming devices you can buy. All of this performance naturally can take its toll on battery life, which is currently not a strong point for the Xperia Z Ultra despite packing a 3050mAh battery.

Sony has already seeded its second firmware update for the device that is reportedly set to help boost battery life along with other tweaks, which hasn't yet rolled out to us for consideration as part of this review. You will get a full day of use out of a charge under normal use out of the Ultra, but this will drop markedly with heavy gaming in particular. It is yet to be revealed whether the software update can also do something to improve the audio output from the small single slit speaker enclosure hidden on the bottom end of the device. Making phone calls and listening to them on speaker is adequate, but the volume could do with a boost when listening to music or watching movies without headphones. Otherwise, music and audio quality through a pair of good headphones is excellent.

Software

Sony runs its own customized version of Android. Typically, Android OEMs like to differentiate their devices by building on Google's Android base by adding their own design and UI tweaks, some of which are heavier than others. Additionally, they like to extend the software features of their devices, which result in the OEM delving deeper into the Android source code than others. Sony adopts an approach that steers towards a more moderate approach to customization, and it's a balance that we are comfortable with in a non-stock Android device. While everyone will have their own view, we think it is one of the better non-stock Android UIs in the market place. It looks good, offers customisation, but remains easy to use.

The UI layer manages to be distinctively Sony in look and feel, yet it doesn't veer too far away from Google's stock Android UI. Changes are present, but they are more subtle and preserve a consistent look and feel through all of the main user interactions with the Xperia Z Ultra. It is attractive and functional, but it does not delve to deeply into the Android source code. Instead Sony has opted to bring additional levels of customization and a Sony user-experience through several pre-installed custom apps that focus on entertainment including music, TV and movies as well as games. This means that when it comes to updating their devices in the wake of a new Android launch from Google, the company has been able to push updates out to users more quickly than it has in the past. It recently detailed its update process to show customers how and why it can take at least some time between a Google release and a Sony product update, which is good PR at the very least.

As with nearly all Android devices, however, you can still customize the Xperia Z Ultra in a whole number of different ways with Sony packing in a range of UI themes, wallpapers and some widgets to help get you started. Sony has also integrated some small multitasking apps/utilities that allow a user to remain in their homescreen or an app for example, when looking to use programs like a calculator, or voice recorder. It is not as extensive as the multitasking apps functions in some devices from Samsung or LG, yet it is still a very handy addition to the Android experience.

In addition to the Xperia Z Ultra's water and dust resistance, Sony has also one other marquee software capability rolled into the Ultra that is not found on its other devices, or those of its main competition. The Xperia Z Ultra also supports stylus input, but unlike Samsung's Wacom co-developed solution, it does not require the use of a purpose-made stylus. Instead, the Xperia Z Ultra can detect and respond to manual input from either a pen or a pencil. To support this functionality, Sony has built in handwriting recognition software that can be used across the operating system.

Blackberry Curve, iPhone 5, Xperia Z Ultra, iPad mini

Final thoughts

It's clear that the Xperia Z Ultra is not aimed at the average mainstream user. Some might argue that it is not clear just exactly who the Xperia Z Ultra is aimed at. It is almost the size of a tablet, yet costs as much as a high-end smartphone, potentially putting it somewhere in a no-man's land. However, like all phablets, it promises to be two devices in one. Its existence also serves to demonstrate that Sony still has the ability to innovate and develop cutting edge devices and is also still willing to take risks.

Even if the Sony Xperia Z Ultra is not for you, there is no doubt that Sony has developed a very interesting and exciting product. Despite its size, it is supremely thin, but well weighted and can be held with reasonable comfort. There are certainly contexts where the Xperia Z Ultra works well from a practical perspective. These include around the office (or a campus) and when commuting on public transport, however, there is no doubt that there are times when using it that you would prefer a more pocketable device. Then again, there are times when using a smaller pocketable device that you can wish you had a device with a larger display. For some users, the Sony Xperia Z Ultra could well be the holy grail of mobile devices.